

#include "stdafx.h"
#include "mymd5.h"
#include <string.h>
#include <stdio.h>

/* Constants for MD5Transform routine. */

#define S11		7
#define S12		12
#define S13		17
#define S14		22
#define S21		5
#define S22		9
#define S23		14
#define S24		20
#define S31		4
#define S32		11
#define S33		16
#define S34		23
#define S41		6
#define S42		10
#define S43		15
#define S44		21

static void MD5Transform(int [4], char[64]);
static void Encode(char *, int *, int);
static void Decode(int *, char *, int);
static void MD5_memcpy(char *, char *, int);
static void MD5_memset(char *, int, int);

static char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
// Rotation is separate from addition to prevent recomputation.
#define FF(a, b, c, d, x, s, ac) { \
 (a) += F ((b), (c), (d)) + (x) + (int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

// MD5 initialization. Begins an MD5 operation, writing a new context. 
void CMyMd5::MD5Init (MyMD5_CTX *context)
{
	context->count[0] = context->count[1] = 0;
	// Load magic initialization constants.
	context->state[0] = 0x67452301;
	context->state[1] = 0xefcdab89;
	context->state[2] = 0x98badcfe;
	context->state[3] = 0x10325476;
}

//  MD5 block update operation. Continues an MD5 message-digest
//  operation, processing another message block, and updating the
//  context.
//  int inputLen  length of input block */
void CMyMd5::MD5Update (MyMD5_CTX *context, char *input, int inputLen)
{
	int i, index, partLen;

	/* Compute number of bytes mod 64 */
	index = (int)((context->count[0] >> 3) & 0x3F);

	/* Update number of bits */
	if ((context->count[0] += ((int)inputLen << 3))
			< ((int)inputLen << 3))
		context->count[1]++;
	context->count[1] += ((int)inputLen >> 29);

	partLen = 64 - index;

	/* Transform as many times as possible.*/
	if (inputLen >= partLen) 
	{
		MD5_memcpy((char *)&context->buffer[index], (char *)input, partLen);
		MD5Transform (context->state, context->buffer);

		for (i = partLen; i + 63 < inputLen; i += 64)
			MD5Transform (context->state, &input[i]);

		index = 0;
	}
	else
		i = 0;

	/* Buffer remaining input */
	MD5_memcpy((char *)&context->buffer[index], (char *)&input[i], inputLen-i);
}

//  MD5 finalization. Ends an MD5 message-digest operation, 
//  writing the the message digest and zeroizing the context.
void CMyMd5::MD5Final(char digest[16], MyMD5_CTX *context)
{
	char bits[8];
	int index, padLen;

	/* Save number of bits */
	Encode (bits, context->count, 8);

	/* Pad out to 56 mod 64.*/
	index = (int)((context->count[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	MD5Update (context, PADDING, padLen);

	/* Append length (before padding) */
	MD5Update (context, bits, 8);

	/* Store state in digest */
	Encode (digest, context->state, 16);

	/* Zeroize sensitive information.*/
	MD5_memset ((char *)context, 0, sizeof (*context));
}

//  MD5 basic transformation. Transforms state based on block.
static void MD5Transform (int state[4], char block[64])
{
	int a = state[0], b = state[1], c = state[2], d = state[3], x[16];

	Decode (x, block, 64);

	/* Round 1 */
	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

	/* Round 4 */
	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;

	/* Zeroize sensitive information. */
	MD5_memset ((char *)x, 0, sizeof (x));
}

//  Encodes input (int) into output (char). Assumes len is
//  a multiple of 4.
static void Encode (char *output, int *input, int len)
{
	int i, j;

	for (i = 0, j = 0; j < len; i++, j += 4) 
	{
		output[j] = (char)(input[i] & 0xff);
		output[j+1] = (char)((input[i] >> 8) & 0xff);
		output[j+2] = (char)((input[i] >> 16) & 0xff);
		output[j+3] = (char)((input[i] >> 24) & 0xff);
	}
}

//  Decodes input (char) into output (int). Assumes len is
//  a multiple of 4.
static void Decode (int *output, char *input, int len)
{
	int i, j;

	for (i=0,j=0; j<len; i++,j+=4)
		output[i] = ((int)input[j]) | (((int)input[j+1]) << 8) |
		(((int)input[j+2]) << 16) | (((int)input[j+3]) << 24);
}


/* Note: Replace "for loop" with standard memcpy if possible. */
static void MD5_memcpy (char * output, char * input, int len)
{
	int i;
	for (i=0; i<len; i++)  output[i]=input[i];
}

/* Note: Replace "for loop" with standard memset if possible. */
static void MD5_memset (char *output, int value, int len)
{
	int i;
	for (i=0; i<len; i++)
	((char *)output)[i] = (char)value;
}

//  ?MD5??????
//  ??:	szSour ????
//			iLen   ??????
//			szDest ???(16??)
void CMyMd5::Md5_Digest(char *szSour, int iLen, char *szDest)
{
	MyMD5_CTX context;

	MD5Init(&context);
	MD5Update(&context, szSour, iLen);
	MD5Final(szDest, &context);
}

CMyMd5::CMyMd5(){}
CMyMd5::~CMyMd5(){}

//success return 0, fail return -1
int CMyMd5::Md5Digest(const unsigned char *pInput, unsigned int unInputLen, unsigned char Digest[16])
{
	if(pInput==0 || unInputLen==0)
		return -1;
	Md5_Digest((char*)pInput, (int)unInputLen, (char*)Digest);
	return 0;
}

//success return 0, fail return -1
int CMyMd5::GetMd5Str(const unsigned char *pInput, unsigned int unInputLen, char *pOutput, unsigned int unOutputLen)
{
	unsigned char Digest[16];
	char chTemp[16];

	if(pInput==0 || pOutput==0 || unInputLen==0 || unOutputLen<32)
		return -1;
	Md5Digest(pInput,unInputLen,Digest);
	*pOutput = '\0';
	for ( int i=0; i < 16; i++) 
	{
		if (Digest[i] == 0)
			strcpy(chTemp,"00");
		else if (Digest[i] <= 15)
			sprintf(chTemp,"0%x",Digest[i]);
		else
			sprintf(chTemp,"%x",Digest[i]);

		if(strlen(chTemp)!=2)
			return -1;
		if(strlen(pOutput)+2>=unOutputLen)
			return -1;
		strcat(pOutput,chTemp);
	}
	return 0;
}


